1. Field of the Invention
The present invention relates to an exhaust gas recirculation valve assembly for controlling recirculation of exhaust gas in an internal combustion engine and, more particularly, to an exhaust gas recirculation valve assembly having valve stem seals configured to protect the shaft-seal interface from contamination.
2. Description of the Relevant Art
Electrically actuated exhaust gas recirculation (EGR) valve assemblies generally require isolation of the actuator assembly from the exhaust gas to assure proper operation. Separation of the actuator from the base comes the need to prevent contamination, by foreign substances present in the engine compartment environment, of the actuator and the valve stem, which extends between the two components. Electrically actuated EGR assemblies heretofore proposed utilize a pair of spring-biased, disc-shaped seals around the openings where the valve stem enters the actuator, and the exhaust gas chamber. This configuration allows lateral movement of the seal to compensate for potential misalignment between the solenoid coil and the base. Such a configuration provides minimal protection to the valve stem which extends between the actuator and the base cover.